Detergent bleach

ABSTRACT

COMPOUNDS OF THE FORMULA   (M-O3S-),(R-OOC-),X-BENZENE   WHERE X IS C6-17, PREFERABLY C8-14, ALKYL OR ACYL; R IS H OR C1-7, ALKYL; M IS ALKALI METAL, AMMONIUM OR SUBSTITUTED AMMONIUM. THE COMPOUNDS UNDERGO PERHYDROLYSIS WITH AQUEOUS HYDROGEN PEROXIDE TO GIVE PERCARBOXYLIC ACIDS WHICH ARE GOOD LOW-TEMPERATURE BLEACHING AGENTS. AS WELL AS BEING BLEACHED PRECURSORS THE COMPOUNDS AND THEIR PERHYDROLYSIS PRODUCTS HAVE DETERGENT PROPERTIES. THE COMPOUNDS ARE THEREFORE SUITED FOR INCORPORATION IN WASHING PRODUCTS.

AU 165 EX 27/66 Cl. 011a 7/18, 7/56 vs. CI. 2: 2- 9,

10 Claims ABSTRACT OF THE DISCLOSURE Compounds of the formula OCOR whereX is C, preferably C alkyl or acyl; R is H or C alkyl; M is alkalimetal, ammonium or substituted ammonium. The compounds undergoperhydrolysis with aqueous hydrogen peroxide to give percarboxylic acidswhich are good low-temperature bleaching agents. As well as beingbleached precursors the compounds and their perhydrolysis products havedetergent properties.

The compounds are therefore suited for incorporation in washingproducts.

This application is a division of our copending US. application Ser. No.610,796, filed Jan. 23, 1967, now abandoned.

This invention relates to detergent and bleaching-aid compounds, and todetergent bleaching compositions, in particular to compositions suitablefor washing textile materials and removing stains therefrom atrelatively low temperatures.

Many detergent compositions contain an inorganic persalt, such as sodiumperborate or percarbonate to provide bleaching properties. Thesepersalts provide a satisfactory bleach when the composition is used ator near the boil, but at lower temperatures, e.g., 50-60 C., theiraction is rather slow, even too slow to be really efiective within thenormal bleaching time. This is particularly disadvantageous when usingwashing machines which operate at this temperature range.

It is known that certain organic esters and acid anhydrides, such asthose obtained by the acylation of phenol sulphonates, have the abilityto enhance the bleaching action at low temperatures of the persalts. Ithas also been suggested to provide detergent bleaching compositionscomprising such esters, an inorganic persalt and an organic detergent,which is either a soap or a soapless detergent, e.g., an alkylbenzenesulphonate or an alkyl sulphate. In such compositions the organicdetergent must be incorporated in a sufficient amount in order that whenthe composition is used the product washes.

It is an object of the present invention to provide a new organicdetergent and bleaching-aid compound of the general formula 3,686,127Patented Au 22, 1972 in which X is a branched or straight chain alkyl oracyl v radical containing 6-17 carbon atoms, R is hydrogen or an alkylradical having 17 carbon atoms and M is an alkali metal, ammonium orsubstituted ammonium radical.

The invention further provides a detergent bleaching compositioncontaining a perhydrate or an inorganic persalt and the above-definedorganic compound. By the term persalt is meant a compound, moreprecisely termed peroxyhydrate, containing hydrogen peroxide ofcrystallization which is liberated when the substance is dissolved inwater. Suitable compountk are alkali metal perborates, percarbonates,perpyrophosphates and persilicates, and also urea peroxide.

It has been found that the compounds according to the invention not onlyenhance the bleaching action of persalts at low temperatures, but alsopossess detergent and emulsifying properties comparable to alkylbenzenesulphonate and hence they are detergent actives having simultaneouslyperacid precursor activity.

During the perhydrolysis reaction the compound according to ourinvention forms percarboxylic acid and the respective phenol sulphonateat relatively low temperature, of which products the former as distinctfrom sodium perborate or H O, has eflicient bleaching activity at lowtemperature and the latter has detergent properties, e.g.,

It has also been found that the solubility and hence the precursoractivity of the new compounds according to the invention decreases withincreasing chain length of the alkyl or acyl radical X.

On the other hand the washing etliciency increases with increasing chainlength of the alkyl or acyl group X.

Suitable compounds giving satisfactory performance are those in'whichthe alkyl or acyl group X contains 6-17 carbon atoms. Compounds in whichX C H or C H CO are almost or completely insoluble in water; compoundsin which X C H or C H CO have poor washingefiiciency. The preferredcompounds are those in which 'X is a branched or straight chain alkyl oracyl radical containing 8-14 carbon atoms.

It has further been found that the new compounds in which the X radicalin the benzene nucleus is in the para positionv to the -OCOR group areparticularly effective. Evidently, in compounds in which the X radicalis in the ortho position to the -0COR group, the perhydrolysis of theacyl group is hampered by the X radical in the ortho position, probablybecause of the steric hindrance. This is also implied by the fact thatthe corresponding ,0- alkyl-phenol sulphonates are always more diflicultto acctylate than the corresponding para isomers.

Although it is known that percarboxylic acids in general are efiicientbleaching agents at lower temperatures, it was found that the bestresults are only obtained from those compounds which on perhydrolysisrelease performic to percaprylic acid, i.e., from those compounds inwhich R is H or an alkyl radical having 1-7 carbon atoms. The preferredcompounds are those in which R is methyl, i.e., acetoxy alkylbenzenesulphonates or acetoxy acylbenzene sulphonates, since they are easy toprepare. They may be prepared by sulphonation of an alkylor acylphenolwith either oleum, S0, or concentrated sulphuric acid and acetylatingthe sulphonate with acetyl chloride or acetic anhydride. The alkylphenolmay be a commercially avilable alkylphenol, e.g., nonylphenol,octylphenol, etc. or may be prepared from phenol through acylation andFries rearrangement to acylphenol followed by reduction.Acetoxy-acylbenzene sulphonates may be obtained by leaving out thereduction step.

The new compounds when combined with an inorganic persalt, such assodium perborate, form detergent bleaching compositions which aresuitable for bleaching and cleansing at relatively low temperatures,e.g., 40-60 C., as well as at higher temperatures.

The invention may also be applied to bleaching baths such as are usedfor treating textiles, to wash liquors, such as are usedin commercial ordomestic laundering. Solid detergent hje'ac I compositions may contain,in addition to a persaltand "the compound according to the invention,inert sii ts g d alkaline agents. An additional amount of organicdetergent, which may be soap and/or an organic anionic and/or nonionictype soapless detergent, may also be incorporated, but is not necessary.

The advantage of the detergent bleaching compositions according to theinvention over compositions which contain mere esters as the bleachenhancer, is that the compound of the invention replaces partially orentirely the use of organic detergent substances, which means that moreroom is available for other ingredients. Besides, the perhydrolysisproducts from the compound of the invention are both valuablesubstances, as distinct from those obtained from the perhydrolysis ofknown esters of which the alcoholic part is more or less an inactivebyproduct.

Detergent bleaching compositions according to the invention shouldpreferably contain one or more alkaline substances in such amounts thatsimilar compositions not containing esters would give a pH value withinthe range 9-11 when dissolved at the desired bleaching concentration.Suitable alkaline materials are, for instance, alkali metal carbonates,phosphates (including orthophosphates and water-soluble condensedphosphates, such as triphosphates and pyrophosphates) and silicates.

Compositions according to the invention may also contain any of theconventional adjuncts present in detergent compositions. As such may bementioned supplementary builders, inert salts and organic materials suchas alkali metal sulphates, chlorides, carboxymethylcellulose,fluorescent agents and germicidal compounds. The compositions must notcontain water in a state and in an amount sufficient to permitappreciable chemical reaction between the components prior to use.

The proportion of the persalt to the new organic compound which may bepresent in compositions according to the invention will depend on thetime and temperature of washing and bleaching, the degree of bleachingrequired and the concentration of the wash and bleaching solution.

In particular it is preferred to use a slight excess of persalt, but atleast an equimolar ratio of persalt to the organic detergent andbleaching-aid compound used is desirable.

It is convenient to measure the precursor activity of compoundsaccording to the invention in terms of peracid yield. The activity ofvarious compounds according to the invention are given in the followingExamples 1 to 7.

The determination is based on iodometric titration of the amount ofperacetic acid which is formed in an aqueous solution at 20' C. from theprecursor and hydrogen peroxide (as sodium perborate). The titration iscarried out at C. after Larious periods of time. At this low temperatureonly the peracid present is titrated, and not the hydrogen peroxide ofwhich an excess is present. As the perhydrolysis is carried out inalkaline medium the peracid formed decomposes during its formation.Therefore, a

maximum is found in the peracid formation as a function of time; thismaximum is regarded as a measure for the precursor activity of thecompound concerned.

Maxi- Maximum mum Boluperacid alter biiity yield (min- 20 Examplepercent utes) pH 8-9 1. Sodium 2-acetexy-6-hexylbenzene sulphonate 43 6Good. 2. Shodlum Z-aeetoxy-G-isooctylbenzene sul- 60 30 Do.

onate. 3. Sodium z-acetoxy-b-nnnylbenzene sul- 45 7 Do.

honate. L odlum 4-acetoxy-3-dodecylbenzene sul- 13 20 Do.

honate. it sodlum 2-aeetnxy-6-dodecylbenzene sul- '26 Do.

phonate.

This seemingly relatively low yield is partly caused by decomposition oithe formed peracid in alkaline medium during the long reaction time.

EXAMPLE 6 The activity of sodium 2-acetoxy 5 caproylbenzene sulphonatewas determined by the same method as described above.

The maximum peracetic acid yield was 39%, which was reached after 10minutes. The compound was found to have a good solubility at 20 C.

EXAMPLE 7 The activity of sodium Z-acetoxy-S-lauroylbenzene sulphonatewas also determined and the maximum peracetic acid yield found was 65%after 10 minutes.

The compound was found to have a good solubility at 20 C.

The above examples clearly show that the compounds in which the alkylgroup is in an ortho position in respect of the acetoxy group having asmaller activity than the corresponding para isomers. It should be notedthat the above tests were carried out at 20 C. and it is clear that withincreasing temperature, e.g., 40-60" C., the maximum peracid yield isreached after a shorter time and the solubility of the compoundsincreases as well.

EXAMPLE 8 To 63 parts of a spray-dried detergent powder base containingthe following materials in parts by weight:

were added 11 parts of sodium perborate tetrahydrate and 26 parts ofsodium Z-acetoxy-S-nonylbenzene sulphonate. The resulting compositionwas thoroughly mixed.

Test swatches stained with immedial black" were washed three times witha solution containing 5.75 g./l. of the above composition during 10minutes at a temperature of 60 C. with a heating-up time of 20 minutes.As compared with the results obtained with the above composition withoutsodium Z-acetoxy-S-nonylbenzene sulphonate there was an increase of 5 inwhiteness degree.

The sodium 2-acetoxy-5-nonylbenzene sulphonate was prepared as follows:

A mixture of 94.7 g. (0.43 mol) commercial nonylphenol and 48.5 g.(0.475 mol) 96% sulphuric acid was stirred for 5 hours at 60-65 C. Afterneutralization with 10% sodium hydroxide solution, extraction with etherof the non-converted nonylphenol and evaporation to dryness of thesulphonate solution, the sulphonate was isolated by extracting theevaporation residue with boiling ethanol.

A mixture of 40 g. crystallized sulphonate and 160 ml. acetic anhydridewas stirred at C. for 2 hours and excess acetic anhydride was thenevaporated under vacuum, followed by sequential extractive evaporationwith ether and carbon tetrachloride.

EXAMPLE 9 Washing tests were carried out in a laboratory washing machineat a dosage of 3 g./l. Cotton test swatches soiled with carbon blackstain were washed, using a bath ratio of 1:50 at temperatures of 60 and95 C., respectively, for 30 minutes per wash. The following whitenessdegrees were measured after three washes:

whiteness degree at- Composition with sodium elkylbenzene sulphonate.Composition with sodium 2-aeetoxy-5-nony1benzene suiphonate What isclaimed is:

1. A detergent bleaching composition which contains 1) an inorganicpersalt selected from the group consisting of alkali metal perborates,alkali metal percarbonates, alkali metal perpyrophosphates and alkalimetal persilicates, and (2) a conjoint organic detergent and bleachprecursor compound of the general formula in which X is a branched orstraight chain alkyl or alkanoyl radical containing 6-17 carbon atoms, Ris a hydrogen or alkyl radical having 1-7 carbon atoms, and M is analkali metal or ammonium radical; said inorganic persalt being presentin at least an equimolar ratio to the said conjoint organic detergentand bleach precursor compound, and said composition being substantiallyfree of water.

6 2. The detergent bleaching composition defined by claim 1 whichfurther contains (3) an alkaline material selected from the groupconsisting of alkali metal car bonates, alkali metal orthophosphates,alkali metal triphosphates, alkali metal pyrophosphates and alkali metalsilicates.

3. The detergent bleaching composition defined by claim 1 wherein theinorganic persalt is sodium perborate.

'4. The detergent bleaching composition defined by claim 1 wherein inthe general formula of the conjoint organic detergent and bleachprecursor compound the R radical is methyl and the X radical in thebenzene nucleus is in the para position to the OCOR group.

5. The detergent bleaching composition defined by claim 2 wherein thealkaline material is a water-soluble pentasodium triphosphate ortetrasodium pyrophosphate.

6. The detergent bleaching composition defined by claim 2 wherein thealkaline material is a water-soluble sodium silicate.

7. The detergent bleaching composition defined by claim 2 which furthercontains (4) an organic detergent selected from the group consisting oforganic nonionie nonsoap detergents, organic anionic nonsoap detergentsand soap.

8. The detergent bleaching composition defined by claim 4 wherein theOCOCH group is in the 2-position and the X radical is in the 5-positionin the benzene nucleus.

9. The detergent bleaching composition defined by claim 8 wherein theconjoint organic detergent and bleach precursor compound is an alkalimetal or ammonium salt of 2-acetoxy-5-nonylbenzene sulphonic acid.

10. The detergent bleaching composition defined by claim 9 wherein theconjoint organic detergent and bleach precursor compound is sodium2-acetoxy-5-nonylbenzene sulphonate.

References Cited UNITED STATES PATENTS 3,532,634 10/1970 Woods 202-99XFOREIGN PATENTS 963,135 12/1961 Great Britain 202-99 MAYER WEINB-LATI,Primary Examiner US. Cl. X.R.

